All-water-based decorative film and preparation method thereof

Abstract

The invention discloses a full-water-based decorative film and a preparation method, and belongs to the technical field of decorative films, and the full-water-based decorative film sequentially comprises a water-based back coating, a printing base material layer, a water-based ink printing layer, a transparent base material layer and a protective layer from bottom to top. By developing and designing a water-based back coating formula, a water-based ink formula and a water-based protective layer material formula, compared with traditional oily back coating, oily ink and oily protective layer materials, VOC emission is greatly reduced, the production environment of the decorative film can be improved, the smell of the decorative film can be reduced, and the decorative film has the advantages of being environmentally friendly and free of pollution. And a healthier use environment is created for a user. According to the preparation method of the full-water-based decorative film, the protective layer, the ink printing layer and the water-based back coating layer are obtained on the transparent base material layer and the printing base material layer through water-based materials in the whole process, emission of VOC is greatly reduced, the full-water-based decorative film is environmentally friendly, the concept of green production is met, the smell of the decorative film can be reduced, and a healthier use environment is created for a user.

Description

Technical Field

[0001] The present invention relates to the technical field of decorative films, and in particular to a fully water-based decorative film and a preparation method thereof. Background Art

[0002] Decorative film is a thin film material used to decorate and protect the surface of objects. It usually has multiple functions and characteristics and can be widely used in many fields such as construction, automobiles, and homes. With the advancement of the national environmental protection strategy and the increasing demand for green and environmentally friendly products, the environmental protection characteristics of decorative films are increasingly valued. However, existing decorative film products, whether it is the protective layer on the surface of the decorative film, the ink printing layer, or the back coating at the bottom of the decorative film, are all produced and processed using oily raw materials. Oily raw materials contain a large amount of solvents such as esters and ketones, and have high VOC (volatile organic compound) emissions, which will make the production environment harsh. In addition, decorative film products have a strong odor and are not environmentally friendly.

[0003] There are also some decorative films produced using water-based raw materials, but the surface performance of the decorative films is poor, the raw materials used still have some VOCs (for example, the water-based UV surface coating treated scratch-resistant PVC decorative film disclosed in the Chinese patent document with publication number CN113603918A uses ethyl acetate as a solvent), the pattern of the water-based ink printing layer is unclear and the bonding strength is low, and the water-based back coating has poor high and low temperature resistance and suffers from delamination and other problems.

[0004] It can be seen that the existing technology still needs to be improved and enhanced. Summary of the invention

[0005] The purpose of the present invention is to provide a fully aqueous decorative film and a preparation method, aiming to solve the problems of poor surface performance of the decorative film produced using existing aqueous raw materials, the raw materials still have some VOC, the aqueous ink printing layer pattern is unclear and the bonding strength is low, and the aqueous back coating has poor high and low temperature resistance and delamination.

[0006] To achieve the above object, the solution provided by the present invention is: A fully aqueous decorative film, the fully aqueous decorative film comprising, from bottom to top, an aqueous back coating layer, a printing substrate layer, an aqueous ink printing layer, a transparent substrate layer and a protective layer; Wherein, the aqueous back coating layer comprises the following components in parts by weight: 45-64 parts of water, 25-30 parts of waterborne polycarbonate polyurethane resin, 5-10 parts of acrylic acid modified waterborne polyurethane resin, 5-10 parts of matting agent, 1-5 parts of thickener; The aqueous ink printing layer comprises the following components in parts by weight: 61-73 parts of water, 18-24 parts of silicone-modified waterborne polyurethane resin, 8-10 parts of pigment, 1-5 parts of wetting agent; The protective layer comprises the following components in parts by weight: 90-95 parts of acrylic modified waterborne polyurethane resin, 3-6 parts of polycarbodiimide, 4-6 parts of hydrophilic aliphatic polyisocyanate, 5-10 parts of diluent, 0.1-1 part of defoaming agent, 0.1-1 part of wetting agent, 0.1-0.5 part of pH adjuster, and 0.01-0.05 part of bactericide.

[0007] Optionally, the matting agent includes fumed aluminum oxide.

[0008] Optionally, the printed substrate layer includes a printed PVC layer or a printed PP layer; and the transparent substrate layer includes a transparent PVC layer or a transparent PP layer.

[0009] The present invention also provides a method for preparing the all-aqueous decorative film, comprising the following steps: S001. The acrylic modified waterborne polyurethane resin, polycarbodiimide, hydrophilic aliphatic polyisocyanate, defoamer, wetting agent, pH adjuster, bactericide and diluent are mixed to obtain a waterborne surface treatment agent; S002. Using a ceramic roller, the aqueous surface treatment agent is transferred to the upper surface of the transparent substrate layer, and dried at 50 to 60°C to cure the aqueous surface treatment agent to form a protective layer; S003. The printed substrate layer is subjected to corona treatment to make the surface tension of the printed substrate layer ≥38dyn / cm; S004. The water, the silicone-modified water-based polyurethane resin, the pigment and the wetting agent are uniformly mixed to obtain a water-based ink; S005. Using a gravure printing plate roller, the aqueous ink is transferred to the upper surface of the printing substrate layer, and dried at 50 to 60° C. to solidify the aqueous ink to form an aqueous ink printing layer; S006. Mix water, waterborne polycarbonate polyurethane resin, acrylic modified waterborne polyurethane resin, matting agent and thickener to obtain a waterborne back coating; S007. Using a ceramic roller, the water-based back coating is transferred to the lower surface of the printed substrate layer, and dried at 50 to 60° C. to cure the water-based back coating to form a water-based back coating; S008. Use a laminating machine to laminate the transparent substrate layer onto the water-based ink printing layer to obtain a fully water-based decorative film.

[0010] Optionally, in step S002, the mesh size of the ceramic roller is 200-260 meshes.

[0011] Optionally, in step S001, the viscosity of the aqueous surface treatment agent is 35-40s in Zain 3# cup.

[0012] Optionally, in step S004, the viscosity of the water-based ink is 20 to 30 seconds in a Caien 3# cup.

[0013] Optionally, in step S005, the mesh depth of the gravure printing plate roller is 15-25 um.

[0014] Optionally, in step S006, the viscosity of the water-based back coating is 32 to 38 seconds in a Zain 3# cup.

[0015] Optionally, in step S007, the mesh size of the ceramic roller is 200-260 meshes.

[0016] The beneficial effects of the present invention are as follows: the present invention provides a fully water-based decorative film, which greatly reduces the emission of volatile organic compounds (VOCs) compared with traditional oily back coatings, oily inks and oily protective layer materials by developing and designing water-based back coating formulas, water-based ink formulas and water-based protective layer material formulas, and can not only improve the production environment of the decorative film, but also reduce the odor of the decorative film, creating a healthier use environment for users; by using two cross-linking agents, hydrophilic aliphatic polyisocyanate and polycarbodiimide, in the water-based protective layer material, the synergistic effect of the hydrophilic aliphatic isocyanate and the polycarbodiimide can be used to further improve the cross-linking degree of the polymer, so that the wear resistance of the water-based protective layer is greatly improved; by using silicone-modified polyurethane resin in the water-based ink material, the interaction between the polar groups on the main chain of the polyurethane and the polar groups on the surface of the transparent substrate layer and the printing substrate layer is used to make the water-based ink printing layer resistant to The transparent substrate layer and the printing substrate layer have high bonding strength, and the silicone segment in the silicone-modified polyurethane resin can significantly reduce the surface tension of the water-based ink, making it easier for the water-based ink to spread on the surface of the printing substrate layer during the printing process, thereby improving the wettability and adhesion of the water-based ink to the printing substrate layer, ensuring that the water-based ink can evenly cover the surface of the printing substrate layer to form a flat, smooth and clear water-based ink printing layer; by simultaneously introducing water-based polycarbonate polyurethane resin and acrylic acid-modified water-based polyurethane resin into the water-based back coating material, and utilizing the synergistic effect of the water-based polycarbonate polyurethane resin and the acrylic acid-modified water-based polyurethane resin, the water-based back coating layer has good high and low temperature resistance, good weather resistance, strong adhesion to the attached object, and is not easy to debond after passing the 75°C / -20°C hot and cold cycle test, ensuring that the water-based back coating layer has good adaptability under various high and low temperature conditions and long-term use.

[0017] The present invention provides a method for preparing a fully aqueous decorative film, wherein aqueous materials are used throughout the process to obtain a protective layer, an ink printing layer and an aqueous back coating layer on a transparent substrate layer and a printed substrate layer, thereby greatly reducing the emission of volatile organic compounds, being environmentally friendly, and complying with the green production concept, and being able to reduce the odor of the decorative film, thereby creating a healthier use environment for users, and by combining a corona treatment process, the bonding ability of the printed substrate layer with the aqueous ink printing layer and the aqueous back coating layer is enhanced, thereby ensuring that each layer is firmly composited, thereby improving the quality and production effect of the aqueous decorative film product as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The present invention is a flow chart of a method for preparing a fully aqueous decorative film.

[0019] Figure 2 It is a schematic diagram of the layered structure of the all-aqueous decorative film provided by the present invention.

[0020] Figure 3 This is a photograph of the surface of the all-water-based decorative film provided in Example 1.

[0021] Figure 4 This is a photograph of the surface of the all-aqueous decorative film provided in Comparative Example 1.

[0022] Figure 5 This is a photograph of the surface of the all-aqueous decorative film provided in Comparative Example 2. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The present invention provides a fully aqueous decorative film, such as Figure 2As shown, the all-water-based decorative film includes, from bottom to top, a water-based back coating layer 1, a printing substrate layer 2, a water-based ink printing layer 3, a transparent substrate layer 4, and a protective layer 5. Among them, the protective layer, as the outermost layer of the all-water-based decorative film, can further enhance the wear resistance, scratch resistance, weather resistance and other properties of the decorative film surface, and improve the service life of the all-water-based decorative film; and the transparent substrate layer plays a role in protecting the water-based ink printing layer, preventing the water-based ink printing layer from being affected by external factors such as scratches, abrasions, and chemical corrosion, while increasing the transparency and glossiness of the water-based decorative film, so that the pattern and color of the printing layer can be more clearly and brightly displayed, and the overall aesthetics of the water-based decorative film is improved. The water-based ink printing layer is the core layer that realizes the function of the water-based decorative film. Through the printing of various colors and patterns, the decorative film is given a rich and diverse appearance effect to meet the aesthetic and decorative needs of different users. The printing substrate layer is the basic material that carries the water-based ink printing layer, providing an attachment surface for the water-based ink, so that the printed pattern and text can be clearly and firmly presented on it. The water-based back coating layer plays a role in closely bonding with the surface of the attached object, ensuring that the all-water-based decorative film can be firmly attached to the attached object. At the same time, the water-based back coating layer can also play a certain protective role on the printed substrate layer, preventing the printed substrate layer from being damaged by external factors.

[0025] Furthermore, the water-based back coating layer comprises the following components in parts by weight: 45-64 parts of water, 25-30 parts of water-based polycarbonate polyurethane resin, 5-10 parts of acrylic acid-modified water-based polyurethane resin, 5-10 parts of matting agent, and 1-5 parts of thickener.

[0026] Among them, water is the main solvent in the water-based back coating, which can dissolve and disperse various other raw materials, so that polymer materials such as water-based polycarbonate polyurethane resin and water-based polyurethane acrylic resin are evenly distributed in the back coating system in fine particles, which is convenient for construction and subsequent film formation, and compared with traditional organic solvents, water does not contain toxic and harmful volatile organic compounds, and will not cause harm to the environment and human health during production, construction and use. The water-based matting agent can enhance the surface tension and wear resistance of the water-based back coating, thereby improving the bonding effect between the water-based back coating and the object to be pasted, as well as protecting the water-based back coating and extending the service life of the decorative film. The thickener can improve the film-forming properties of the water-based back coating, so that the water-based back coating can form a more dense and uniform film structure during the curing and drying process, and improve the strength and adhesion of the water-based back coating.

[0027] The soft segment of the waterborne polycarbonate polyurethane resin is composed of polycarbonate polyols, the carbonate groups on the molecular chain are chemically stable, and are not prone to chemical bond breakage and degradation at high temperatures. At the same time, the integrity of the molecular chain can be maintained at low temperatures, and it is not prone to brittle cracking. In addition, the urethane bonds in the polyurethane molecular chain can form a large number of hydrogen bonds, which can limit the movement of the molecular chain at high temperatures, improve the stability of the material, and enable the material to withstand higher temperatures. Moreover, at low temperatures, the hydrogen bonds can enhance the interaction between the molecular chains, prevent the molecular chains from being too hard due to the low temperature, and enable the material to maintain a certain degree of flexibility. Therefore, the waterborne polycarbonate polyurethane resin has good high and low temperature resistance. The acrylic acid modified waterborne polyurethane resin has an acrylate double bond, which can form a highly cross-linked network structure after curing, and this cross-linked structure can enhance the chemical resistance and anti-aging performance of the resin, thereby improving the weather resistance of the waterborne back coating, and the acrylic acid modified waterborne polyurethane resin contains a large number of polar groups, such as hydroxyl and amino groups, and these polar groups can form hydrogen bonds, van der Waals forces and other forces with polar groups or atoms on the surface of the attached object, thereby increasing the adhesion of the waterborne back coating to the surface of the attached object. It can be seen that the present invention introduces waterborne polycarbonate type polyurethane resin and acrylic acid modified waterborne polyurethane resin into the material system of the waterborne back coating at the same time, and utilizes the synergistic effect of waterborne polycarbonate type polyurethane resin and acrylic acid modified waterborne polyurethane resin, so that the waterborne back coating has good high temperature resistance and low temperature resistance, and good weather resistance, strong adhesion to the attached object, and is not easy to debond, thereby ensuring that the waterborne back coating has good adaptability under various high and low temperature conditions and long-term use.

[0028] Furthermore, the water-based ink printing layer comprises the following components in parts by weight: 61 to 73 parts of water, 18 to 24 parts of silicone-modified water-based polyurethane resin, 8 to 10 parts of pigment, and 1 to 5 parts of wetting agent.

[0029] Among them, water is used as a solvent to make the silicone-modified polyurethane resin and the pigment uniformly mixed to form an ink system with good fluidity; and by adjusting the amount of water added, the concentration and viscosity of the water-based ink can be controlled, so that the water-based ink can be suitable for the printing equipment and process of the water-based decorative film. The wetting agent can adjust the rheology of the water-based ink, so that the water-based ink has good transferability and can ensure the pattern clarity of the water-based ink printing layer. The silicone-modified waterborne polyurethane resin has a polyurethane main chain and silicone segments, wherein the polyurethane main chain contains a large number of polar groups such as urethane bonds (-NHCOO-), and these polar groups can interact with polar groups on the surface of the transparent substrate layer and the printing substrate layer through hydrogen bonds, van der Waals forces, etc., so that the water-based ink is firmly attached to the transparent substrate layer and the printing substrate layer, so that the water-based ink printing layer has high bonding strength to the transparent substrate layer and the printing substrate layer, and the silicone segment can significantly reduce the surface tension of the water-based ink, so that the water-based ink is easier to spread on the surface of the printing substrate layer during the printing process, improve the wettability and adhesion of the water-based ink to the printing substrate layer, ensure that the water-based ink can evenly cover the surface of the printing substrate layer, and form a flat, smooth and clear water-based ink printing layer.

[0030] Furthermore, the protective layer includes the following components in parts by weight: 90-95 parts of acrylic modified waterborne polyurethane resin, 3-6 parts of polycarbodiimide, 4-6 parts of hydrophilic aliphatic polyisocyanate, 5-10 parts of diluent, 0.1-1 part of defoaming agent, 0.1-1 part of wetting agent, 0.1-0.5 part of pH adjuster, and 0.01-0.05 part of bactericide.

[0031] Among them, the acrylic modified waterborne polyurethane resin provides the basic film-forming properties of the protective layer, wherein the polyurethane part gives the protective layer good flexibility, wear resistance and chemical resistance, and the introduction of acrylic monomers in the resin can improve the hardness and weather resistance of the protective layer, so that the protective layer can better resist the erosion of the external environment, and can effectively protect the layers below the protective layer of the decorative film. The hydrophilic aliphatic isocyanate can participate in the cross-linking reaction with the hydroxyl groups in the polyurethane resin, improve the cross-linking degree of the polymer, thereby giving the protective layer good wear resistance, and the hydrophilic aliphatic isocyanate can give the protective film good water resistance and yellowing resistance, so that the decorative film is not easy to yellow in a humid environment or during long-term use. The polycarbodiimide as a cross-linking agent can undergo a cross-linking reaction with the carboxyl group in the polyurethane resin, and synergistically act with the hydrophilic aliphatic isocyanate to further improve the cross-linking degree of the polymer, so that the wear resistance of the protective layer is greatly improved.

[0032] Optionally, the matting agent includes vapor-phase alumina, which has a high specific surface area and can enhance the wear resistance and surface tension of the water-based back coating, thereby protecting the water-based back coating and increasing the bonding effect between the water-based back coating and the adhered object, extending the service life of the decorative film. In addition, vapor-phase alumina has good temperature resistance and can meet the high-temperature bonding requirements of the water-based decorative film production process and various customer application conditions.

[0033] Optionally, the printed substrate layer includes a printed PVC layer or a printed PP layer; the transparent substrate layer includes a transparent PVC layer or a transparent PP layer, so that the fully aqueous decorative film can use not only PVC film as the base film, but also other types of film materials as the base film of the aqueous decorative film.

[0034] The present invention provides a fully water-based decorative film. By developing and designing a water-based back coating formula, a water-based ink formula and a water-based protective layer material (water-based surface treatment agent) formula, compared with traditional oil-based back coating, oil-based ink and oil-based protective layer material, the emission of volatile organic compounds (VOC) is greatly reduced, which can not only improve the production environment of the decorative film, but also reduce the odor of the decorative film, creating a healthier use environment for users; by using two cross-linking agents, hydrophilic aliphatic polyisocyanate and polycarbodiimide, in the water-based protective layer material, the synergistic effect of the hydrophilic aliphatic isocyanate and the polycarbodiimide can be used to further improve the cross-linking degree of the polymer, so that the wear resistance of the water-based protective layer is greatly improved; by using an organosilicon-modified polyurethane resin in the water-based ink material, the interaction between the polar groups on the main chain of the polyurethane and the polar groups on the surface of the transparent substrate layer and the printing substrate layer is used to make the water-based ink printing layer resistant to The transparent substrate layer and the printing substrate layer have high bonding strength, and the silicone segment in the silicone-modified polyurethane resin can significantly reduce the surface tension of the water-based ink, making it easier for the water-based ink to spread on the surface of the printing substrate layer during the printing process, thereby improving the wettability and adhesion of the water-based ink to the printing substrate layer, ensuring that the water-based ink can evenly cover the surface of the printing substrate layer to form a flat, smooth and clear water-based ink printing layer; by simultaneously introducing water-based polycarbonate polyurethane resin and acrylic acid-modified water-based polyurethane resin into the water-based back coating material, and utilizing the synergistic effect of the water-based polycarbonate polyurethane resin and the acrylic acid-modified water-based polyurethane resin, the water-based back coating layer has good high and low temperature resistance, good weather resistance, strong adhesion to the attached object, and is not easy to debond after passing the 75°C / -20°C hot and cold cycle test, ensuring that the water-based back coating layer has good adaptability under various high and low temperature conditions and long-term use.

[0035] like Figure 1 As shown, the present invention also provides a method for preparing the all-aqueous decorative film, comprising the following steps: S001. The acrylic modified waterborne polyurethane resin, polycarbodiimide, hydrophilic aliphatic polyisocyanate, defoamer, wetting agent, pH adjuster, bactericide and diluent are mixed to obtain a waterborne surface treatment agent; S002. Use a ceramic roller to transfer the water-based surface treatment agent to the upper surface of the transparent substrate layer, and dry it at 50-60°C to solidify the water-based surface treatment agent to form a protective layer. In this step, when the drying and curing temperature of the water-based surface treatment agent is too low, the water in the water-based surface treatment agent cannot be fully volatilized, and tiny pores and defects will be formed inside the protective layer, reducing the compactness of the protective layer, and reducing the waterproof and moisture-proof capabilities of the decorative film. When the drying and curing temperature is too low, the cross-linking reaction between the cross-linking agent and the polyurethane resin is incomplete, resulting in poor wear resistance of the protective layer, and the bonding strength of the protective layer to the transparent substrate layer will also deteriorate; when the drying temperature of the water-based surface treatment agent is too high, the shrinkage rate of the protective layer will increase, affecting the dimensional stability of the decorative film; S003. Perform corona treatment on the printing substrate layer to make the surface tension of the printing substrate layer ≥38dyn / cm, to avoid the surface tension of the printing substrate layer being too small, so that the water-based ink can be evenly spread and adhered when transferred to the surface of the printing substrate layer, and to ensure that the pattern of the water-based ink printing layer is clearly printed; S004. The water, the silicone-modified water-based polyurethane resin, the pigment and the wetting agent are uniformly mixed to obtain a water-based ink; S005. Use a gravure printing plate roller to transfer the water-based ink to the upper surface of the printing substrate layer, and dry it at 50-60°C to solidify the water-based ink to form a water-based ink printing layer. In this step, if the drying and curing temperature of the water-based ink is too low, the water-based ink cannot be fully cured, and the chemical bonding and physical adsorption between the water-based ink and the printing substrate layer cannot be effectively formed, resulting in insufficient adhesion between the water-based ink and the printing substrate layer. During the subsequent processing, transportation or use of the decorative film, the water-based ink printing layer is prone to peeling and falling off, affecting the quality and service life of the decorative film product. If the drying and curing temperature of the water-based ink is too high, it is easy to cause the pigment in the water-based ink to undergo chemical reactions such as thermal decomposition and oxidation, resulting in changes in the ink color, and the expected printing color effect cannot be achieved, affecting the visual quality of the decorative film product.

[0036] S006. Mix water, waterborne polycarbonate polyurethane resin, acrylic modified waterborne polyurethane resin, matting agent and thickener to obtain a waterborne back coating; S007. Use a ceramic roller to transfer the water-based back coating to the lower surface of the printed substrate layer, and dry it at 50-60°C to cure the water-based back coating to form a water-based back coating layer. In this step, when the drying and curing temperature of the water-based back coating is too low, the water and solvent in the water-based back coating cannot be fully volatilized, and the residual solvent will weaken the cohesion of the water-based back coating layer, reduce the strength and durability of the water-based back coating layer, and incomplete curing of the water-based back coating will make the mechanical properties of the water-based back coating such as hardness and flexibility fail to meet the expected requirements.

[0037] S008. Use a laminating machine to laminate the transparent substrate layer onto the water-based ink printing layer to obtain a fully water-based decorative film.

[0038] The present invention provides a method for preparing a fully aqueous decorative film, wherein aqueous materials are used throughout the process to obtain a protective layer, an ink printing layer and an aqueous back coating layer on a transparent substrate layer and a printed substrate layer, thereby greatly reducing the emission of volatile organic compounds, being environmentally friendly, and complying with the green production concept, and being able to reduce the odor of the decorative film, thereby creating a healthier use environment for users, and by combining a corona treatment process, the bonding ability of the printed substrate layer with the aqueous ink printing layer and the aqueous back coating layer is enhanced, thereby ensuring that each layer is firmly composited, thereby improving the quality and production effect of the aqueous decorative film product as a whole.

[0039] Optionally, in step S002, the mesh number of the ceramic roller is 200 to 260. The mesh number of the ceramic roller reflects the number of openings per unit area on the surface of the ceramic roller. When the mesh number of the ceramic roller is greater than 260, the amount of the water-based surface treatment agent transferred to the transparent substrate layer by the ceramic roller is small, and the scratch and wear resistance of the surface of the water-based decorative film, i.e., the protective layer, is poor; and when the mesh number of the ceramic roller is less than 200, the water-based surface treatment agent will be distributed on the surface of the transparent substrate layer in relatively large droplets, which is difficult to spread evenly, resulting in large fluctuations on the surface of the protective layer, and unable to form a delicate and smooth surface state. Therefore, in step S002, by controlling the mesh number of the ceramic roller to 200 to 260, the surface appearance of the protective layer can be guaranteed to be delicate, and the wear resistance of the protective layer is good.

[0040] Optionally, in step S001, the viscosity of the aqueous surface treatment agent is 35 to 40 seconds per Cai En 3# cup. When the viscosity of the aqueous surface treatment agent is high, it is not conducive to the transfer of the aqueous surface treatment agent to the transparent substrate layer, resulting in the accumulation of the aqueous surface treatment agent on the ceramic roller, causing granular appearance defects on the surface of the aqueous decorative film, i.e., the surface of the protective layer; and when the viscosity of the aqueous surface treatment agent is low, the fluidity of the aqueous surface treatment agent is too large, which will cause obvious reticulation on the surface of the aqueous decorative film. Therefore, in step S001, the viscosity of the aqueous surface treatment agent is adjusted by using a diluent (the diluent can be ethanol) so that the viscosity of the aqueous surface treatment agent is controlled at 35 to 40 seconds per Cai En 3# cup, which can ensure that the surface of the protective layer will not produce obvious reticulation and appearance defects.

[0041] In order to ensure the good fluidity of the water-based ink and to ensure good transfer to the printing substrate layer, optionally, in step S004, the viscosity of the water-based ink is controlled at 20 to 30 seconds in a Zain 3# cup, thereby avoiding the appearance of coarse reticulation in the water-based ink printing layer and ensuring that the pattern on the water-based ink printing layer is clear.

[0042] Optionally, in step S005, the mesh depth of the gravure printing plate roller is 15 to 25 um. If the mesh of the gravure printing plate roller is too shallow, the amount of water-based ink transferred to the printing substrate layer will be too small, and the saturation of the printed pattern will not be high; and if the printing mesh depth is too deep, the water-based ink will not be transferred in time and the mesh will be easily blocked, which will not only cause inconvenience in cleaning the gravure printing plate roller, but also cause appearance defects to the water-based ink layer. Therefore, in order to avoid the above problems, step S005 preferably uses a gravure printing plate roller with a mesh depth of 15 to 25 um.

[0043] Optionally, in step S006, the viscosity of the water-based back coating is 32 to 38 seconds per Cai En 3# cup. When the viscosity of the water-based back coating is low, the amount of the water-based back coating transferred to the printed substrate layer is small, which will result in insufficient thickness of the water-based back coating layer, and it will not be able to provide sufficient bonding strength to the printed substrate layer and the surface of the adhered object; and when the viscosity of the water-based back coating is high, it is not conducive to the transfer of the water-based back coating to the printed substrate layer, and it is easy to cause granular appearance defects on the surface of the printed substrate layer. Therefore, in order to enable the water-based back coating layer to provide sufficient bonding strength to the printed substrate layer and the surface of the adhered object at the same time, in step S006, the viscosity of the water-based back coating is controlled at 32 to 38 seconds per Cai En 3# cup.

[0044] Optionally, in order to ensure that the amount of water-based back coating transferred to the printed substrate layer is sufficient, to ensure that the water-based back coating layer can provide sufficient bonding strength to both the printed substrate layer and the surface of the adhered object, and that the water-based back coating layer does not have obvious appearance defects, in step S007, the mesh size of the ceramic roller is 200 to 260 meshes.

[0045] In order to further illustrate the all-aqueous decorative film and preparation method provided by the present invention, the following examples and comparative examples are provided.

[0046] Example 1 This embodiment provides a fully aqueous decorative film, which comprises, from bottom to top, an aqueous back coating layer, a printing substrate layer, an aqueous ink printing layer, a transparent substrate layer, and a protective layer; The raw materials for preparing the water-based back coating layer are composed of the following raw materials in parts by weight: 45 parts of water, 25 parts of water-based polycarbonate polyurethane resin, 5 parts of acrylic acid-modified water-based polyurethane resin, 5 parts of fumed alumina, and 1 part of thickener; The raw materials for preparing the water-based ink printing layer are composed of the following raw materials in parts by weight: 61 parts of water, 18 parts of silicone-modified water-based polyurethane resin, 8 parts of pigment, and 1 part of wetting agent; The raw materials for preparing the protective layer are composed of the following raw materials in parts by weight: 90 parts of acrylic modified waterborne polyurethane resin, 3 parts of polycarbodiimide, 4 parts of hydrophilic aliphatic polyisocyanate, 5 parts of diluent, 0.1 parts of defoamer, 0.1 parts of wetting agent, 0.1 parts of pH adjuster, and 0.01 parts of bactericide.

[0047] This embodiment also provides a method for preparing a fully aqueous decorative film, comprising the following steps: S001. The acrylic modified waterborne polyurethane resin, polycarbodiimide, hydrophilic aliphatic polyisocyanate, defoamer, wetting agent, pH adjuster, bactericide and diluent are mixed to obtain a waterborne surface treatment agent having a viscosity of 35s of Cai En 3# cup; S002. The water-based surface treatment agent is transferred to the upper surface of the transparent substrate layer using a ceramic roller with a mesh size of 200, and dried at 50 to 60 ° C to cure the water-based surface treatment agent to form a protective layer; S003. The printed substrate layer is subjected to corona treatment to make the surface tension of the printed substrate layer ≥38dyn / cm; S004. The water, the silicone-modified waterborne polyurethane resin, the pigment and the wetting agent are mixed to obtain a water-based ink having a viscosity of 25s of Cai En 3# cup; S005. The water-based ink is transferred to the upper surface of the printing substrate layer using a gravure printing plate roller having a mesh depth of 20 um, and dried at 50 to 60 ° C to solidify the water-based ink to form a water-based ink printing layer; S006. The water, waterborne polycarbonate polyurethane resin, acrylic modified waterborne polyurethane resin, matting agent, thickener were mixed to obtain a waterborne back coating, the viscosity of the waterborne back coating was Cai En 3# cup 35s; S007. Using a 220-mesh ceramic roller, the aqueous back coating is transferred to the lower surface of the printed substrate layer, and dried at 50 to 60° C. to cure the aqueous back coating to form an aqueous back coating; S008. Use a laminating machine to laminate the transparent substrate layer onto the water-based ink printing layer to obtain a fully water-based decorative film.

[0048] Example 2 This embodiment provides a fully aqueous decorative film, which comprises, from bottom to top, an aqueous back coating layer, a printing substrate layer, an aqueous ink printing layer, a transparent substrate layer, and a protective layer; The raw materials for preparing the water-based back coating layer are composed of the following raw materials in parts by weight: 50 parts of water, 27 parts of water-based polycarbonate polyurethane resin, 8 parts of acrylic acid-modified water-based polyurethane resin, 7 parts of fumed alumina, and 3 parts of thickener; The raw materials for preparing the water-based ink printing layer are composed of the following raw materials in parts by weight: 70 parts of water, 20 parts of silicone-modified water-based polyurethane resin, 9 parts of pigment, and 3 parts of wetting agent; The raw materials for preparing the protective layer are composed of the following raw materials in parts by weight: 92 parts of acrylic modified waterborne polyurethane resin, 5 parts of polycarbodiimide, 5 parts of hydrophilic aliphatic polyisocyanate, 7 parts of diluent, 0.5 parts of defoamer, 0.5 parts of wetting agent, 0.3 parts of pH adjuster, and 0.03 parts of bactericide.

[0049] This embodiment also provides a method for preparing a fully aqueous decorative film, wherein steps S003 to S008 are the same as those in embodiment 1; step S001 is different from embodiment 1 in that the viscosity of the aqueous surface treatment agent is 38s per Zain 3# cup; step S002 is different from embodiment 1 in that the mesh size of the ceramic roller is 260 meshes.

[0050] Example 3 This embodiment provides a fully aqueous decorative film, which comprises, from bottom to top, an aqueous back coating layer, a printing substrate layer, an aqueous ink printing layer, a transparent substrate layer, and a protective layer; The raw materials for preparing the water-based back coating layer are composed of the following raw materials in parts by weight: 64 parts of water, 30 parts of water-based polycarbonate polyurethane resin, 10 parts of acrylic acid-modified water-based polyurethane resin, 10 parts of fumed alumina, and 5 parts of thickener; The raw materials for preparing the water-based ink printing layer are composed of the following raw materials in parts by weight: 73 parts of water, 24 parts of silicone-modified water-based polyurethane resin, 10 parts of pigment, and 5 parts of wetting agent; The raw materials for preparing the protective layer are composed of the following raw materials in parts by weight: 95 parts of acrylic modified waterborne polyurethane resin, 6 parts of polycarbodiimide, 6 parts of hydrophilic aliphatic polyisocyanate, 10 parts of diluent, 1 part of defoamer, 1 part of wetting agent, 0.5 parts of pH adjuster, and 0.05 parts of bactericide.

[0051] This embodiment also provides a method for preparing a fully aqueous decorative film. The method for preparing a fully aqueous decorative film provided is the same as the method for preparing a fully aqueous decorative film provided in Example 1.

[0052] Comparative Example 1 This comparative example provides a fully aqueous decorative film, which includes, from bottom to top, an aqueous back coating layer, a printing substrate layer, an aqueous ink printing layer, a transparent substrate layer and a protective layer; the raw materials for preparing the aqueous back coating layer are the same as those in Example 1, the raw materials for preparing the aqueous ink printing layer are the same as those in Example 1, and the raw materials for preparing the protective layer are the same as those in Example 1.

[0053] This comparative example also provides a method for preparing a fully aqueous decorative film. The difference between the method for preparing a fully aqueous decorative film provided and the method for preparing a fully aqueous decorative film provided in Example 1 is that in step S001, the viscosity of the aqueous surface treatment agent is 30s of Zain 3# cup.

[0054] Comparative Example 2 This comparative example provides a fully aqueous decorative film, which includes, from bottom to top, an aqueous back coating layer, a printing substrate layer, an aqueous ink printing layer, a transparent substrate layer and a protective layer; the raw materials for preparing the aqueous back coating layer are the same as those in Example 1, the raw materials for preparing the aqueous ink printing layer are the same as those in Example 1, and the raw materials for preparing the protective layer are the same as those in Example 1.

[0055] This comparative example also provides a method for preparing a fully aqueous decorative film. The difference between the method for preparing a fully aqueous decorative film provided and the method for preparing a fully aqueous decorative film provided in Example 1 is that in step S002, the mesh number of the ceramic roller is 180 meshes.

[0056] Comparative Example 3 This comparative example provides a fully aqueous decorative film, which includes, from bottom to top, an aqueous back coating layer, a printing substrate layer, an aqueous ink printing layer, a transparent substrate layer and a protective layer; the raw materials for preparing the aqueous back coating layer are the same as those in Example 1, the raw materials for preparing the aqueous ink printing layer are the same as those in Example 1, and the raw materials for preparing the protective layer are the same as those in Example 1.

[0057] This comparative example also provides a method for preparing a fully aqueous decorative film. The difference between the method for preparing a fully aqueous decorative film provided and the method for preparing a fully aqueous decorative film provided in Example 1 is that in step S002, the mesh number of the ceramic roller is 280 meshes.

[0058] Comparative Example 4 The present comparative example provides a fully aqueous decorative film, which comprises, from bottom to top, an aqueous back coating layer, a printing substrate layer, an aqueous ink printing layer, a transparent substrate layer and a protective layer; the raw materials for preparing the aqueous back coating layer are the same as those in Example 1, the raw materials for preparing the aqueous ink printing layer are the same as those in Example 1, and the raw materials for preparing the protective layer are composed of the following raw materials in parts by weight: 90 parts of acrylic modified aqueous polyurethane resin, 7 parts of hydrophilic aliphatic polyisocyanate, 5 parts of diluent, 0.1 parts of defoaming agent, 0.1 parts of wetting agent, 0.1 parts of pH adjuster, and 0.01 parts of bactericide.

[0059] This comparative example also provides a method for preparing a fully aqueous decorative film, and the method for preparing the fully aqueous decorative film provided is the same as the method for preparing the fully aqueous decorative film provided in Example 1.

[0060] Comparative Example 5 This comparative example provides a fully aqueous decorative film, which includes, from bottom to top, an aqueous back coating layer, a printing substrate layer, an aqueous ink printing layer, a transparent substrate layer and a protective layer; the raw materials for preparing the aqueous back coating layer are the same as those in Example 1, the raw materials for preparing the protective layer are the same as those in Example 1, and the raw materials for preparing the aqueous ink printing layer are composed of the following raw materials in parts by weight: 61 parts of water, 5 parts of silicone-modified aqueous polyurethane resin, 8 parts of pigment, and 1 part of wetting agent.

[0061] This comparative example also provides a method for preparing a fully aqueous decorative film, and the method for preparing the fully aqueous decorative film provided is the same as the method for preparing the fully aqueous decorative film provided in Example 1.

[0062] Comparative Example 6 This comparative example provides a fully aqueous decorative film, which includes, from bottom to top, an aqueous back coating layer, a printing substrate layer, an aqueous ink printing layer, a transparent substrate layer and a protective layer; the raw materials for preparing the aqueous back coating layer are the same as those in Example 1, the raw materials for preparing the protective layer are the same as those in Example 1, and the raw materials for preparing the aqueous ink printing layer are composed of the following raw materials in parts by weight: 61 parts of water, 30 parts of silicone-modified aqueous polyurethane resin, 8 parts of pigment, and 1 part of wetting agent.

[0063] This comparative example also provides a method for preparing a fully aqueous decorative film, and the method for preparing the fully aqueous decorative film provided is the same as the method for preparing the fully aqueous decorative film provided in Example 1.

[0064] Comparative Example 7 This comparative example provides a fully aqueous decorative film, which includes, from bottom to top, an aqueous back coating layer, a printing substrate layer, an aqueous ink printing layer, a transparent substrate layer and a protective layer; the raw materials for preparing the protective layer are the same as those in Example 1, the raw materials for preparing the aqueous ink printing layer are the same as those in Example 1, and the raw materials for preparing the aqueous back coating layer are composed of the following raw materials in parts by weight: 45 parts of water, 30 parts of acrylic acid-modified aqueous polyurethane resin, 5 parts of fumed alumina, and 1 part of thickener.

[0065] This comparative example also provides a method for preparing a fully aqueous decorative film, and the method for preparing the fully aqueous decorative film provided is the same as the method for preparing the fully aqueous decorative film provided in Example 1.

[0066] Comparative Example 8 This comparative example provides a fully aqueous decorative film, which includes, from bottom to top, an aqueous back coating layer, a printing substrate layer, an aqueous ink printing layer, a transparent substrate layer and a protective layer; the raw materials for preparing the protective layer are the same as those in Example 1, the raw materials for preparing the aqueous ink printing layer are the same as those in Example 1, and the raw materials for preparing the aqueous back coating layer are composed of the following raw materials in parts by weight: 45 parts of water, 30 parts of aqueous polycarbonate polyurethane resin, 5 parts of fumed alumina, and 1 part of thickener.

[0067] This comparative example also provides a method for preparing a fully aqueous decorative film, and the method for preparing the fully aqueous decorative film provided is the same as the method for preparing the fully aqueous decorative film provided in Example 1.

[0068] Obtain Example 1 (see Figure 3 ) provided by the all-water-based decorative film and comparative example 1 (see Figure 4 ) and Comparative Example 2 (see Figure 5 ) provided photos of the surface of the all-water-based decorative film (i.e. the surface of the protective layer), from Figure 4 From the photos of the surface of the all-water decorative film provided, it can be seen that the surface of the all-water decorative film provided in Comparative Example 1 has obvious reticulation. This is because the viscosity of the water-based treatment agent is too low and the fluidity of the water-based surface treatment agent is too high, which will cause obvious reticulation on the surface of the water-based decorative film. Figure 5 It can be seen from the photos of the surface of the all-aqueous decorative film provided that the surface appearance of the all-aqueous decorative film provided in Comparative Example 2 is not delicate enough. This is because the ceramic roller used to transfer the aqueous treatment agent has a small mesh number, and the aqueous surface treatment agent will be distributed on the surface of the transparent substrate layer in the form of relatively large droplets, which is difficult to spread evenly, resulting in large undulations on the surface of the protective layer, and unable to form a delicate and smooth surface state.

[0069] According to the provisions of the standard "GB / T 17657-2022 Test methods for physical and chemical properties of artificial boards and veneered artificial boards", the scratch resistance and wear resistance of the all-aqueous decorative film surfaces provided in Examples 1 to 3 and the all-aqueous decorative film surfaces (i.e., protective layers) provided in Comparative Examples 3 and 4 were tested respectively, and the test results are shown in Table 1.

[0070] Table 1:

[0071] It can be seen from the test results in Table 1 that the scratch resistance and wear resistance data of the surface of the all-aqueous decorative film provided in Comparative Example 3 are not as good as the scratch resistance and film resistance of the surface of the all-aqueous decorative film provided in Examples 1 to 3. This is because the ceramic roller used to transfer the aqueous treatment agent has a large mesh number, and the amount of the aqueous surface treatment agent transferred to the transparent substrate layer by the ceramic roller is small; and the scratch resistance and wear resistance data of the surface of the all-aqueous decorative film provided in Comparative Example 4 are also not as good as the scratch resistance and film resistance of the surface of the all-aqueous decorative film provided in Examples 1 to 3. This is because Comparative Example 4 does not use two cross-linking agents at the same time to cross-link with the acrylic modified aqueous polyurethane resin, so that the cross-linking degree of the polymer is limited.

[0072] According to the standard "GB / T 8808 Test Method for Peel Strength of Plastic Composite Films", the interlayer peel strength between the transparent substrate layer and the aqueous ink layer in the fully aqueous decorative films provided in Examples 1 to 3 and the fully aqueous decorative films provided in Comparative Examples 5 and 6 was tested, and the pattern in the ink printing layer was visually observed. The observation and test results are shown in Table 2

[0073] Table 2:

[0074] From the test results in Table 2, it can be seen that in the decorative film provided by Comparative Example 5, the interlayer peeling strength value between the water-based ink layer and the transparent substrate layer is low, and the saturation of the printed layer pattern is insufficient. This is because in Comparative Example 5, the amount of organosilicon-modified water-based polyurethane resin in the water-based ink used is small, and the wettability and adhesion of the water-based ink to the printed substrate layer are low, making it easy for the transparent substrate layer and the water-based ink layer to peel off during the test. In the decorative film provided by Comparative Example 6, although the interlayer peeling strength value between the water-based ink layer and the transparent substrate layer is high, the pattern of the water-based ink printed layer is not clear enough. This is because in Comparative Example 6, the amount of organosilicon-modified water-based polyurethane resin in the water-based ink used is large, which increases the viscosity of the water-based ink and makes the fluidity of the water-based ink worse. During the transfer process of the gravure printing plate roller, it is difficult to smoothly fill it into the mesh of the gravure printing plate roller, resulting in insufficient amount of water-based ink transferred to the printed substrate layer and insufficient pattern of the printed layer.

[0075] According to the test method specified in the standard "GB / T 17657-2022 Test methods for physical and chemical properties of artificial boards and veneered artificial boards", the water-based back coatings of the all-water-based decorative films provided in Examples 1 to 3 and the water-based back coatings of the all-water-based decorative films provided in Comparative Examples 7 and 8 were subjected to hot and cold cycle tests. The test temperature conditions were 75°C / -20°C, and the test results are shown in Table 3.

[0076] According to the test method specified in the standard "GB / T 9286-2021 Cross-cut test for paint and varnish films", the adhesion of the water-based back coating layer of the all-water-based decorative film provided in Examples 1 to 3 to the printed substrate layer and the adhesion of the water-based back coating layer of the all-water-based decorative film provided in Comparative Examples 7 and 8 to the printed substrate layer were tested, and the test results are shown in Table 3.

[0077] Table 3:

[0078] It can be seen from the test results in Table 3 that the water-based back coating layer of the all-water-based decorative film provided by Comparative Example 7 has a debonding problem after a 75°C / -20°C hot and cold cycle test, while the adhesion of the water-based back coating layer of the all-water-based decorative film provided by Comparative Example 8 is not as good as that of Examples 1 to 3 and Comparative Example 7. This is because the water-based polycarbonate polyurethane resin and the acrylic modified water-based polyurethane resin are not simultaneously introduced into the material system of the water-based back coating layer, so that the water-based back coating layer cannot simultaneously take into account good high / low temperature resistance and strong adhesion.

[0079] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A fully aqueous decorative film, characterized in that: The all-water-based decorative film comprises, from bottom to top, a water-based back coating layer, a printing substrate layer, a water-based ink printing layer, a transparent substrate layer and a protective layer; Wherein, the aqueous back coating layer comprises the following components in parts by weight: 45-64 parts of water, 25-30 parts of waterborne polycarbonate polyurethane resin, 5-10 parts of acrylic acid modified waterborne polyurethane resin, 5-10 parts of matting agent, 1-5 parts of thickener; The aqueous ink printing layer comprises the following components in parts by weight: 61-73 parts of water, 18-24 parts of silicone-modified waterborne polyurethane resin, 8-10 parts of pigment, 1-5 parts of wetting agent; The protective layer comprises the following components in parts by weight: 90-95 parts of acrylic modified waterborne polyurethane resin, 3-6 parts of polycarbodiimide, 4-6 parts of hydrophilic aliphatic polyisocyanate, 5-10 parts of diluent, 0.1-1 part of defoaming agent, 0.1-1 part of wetting agent, 0.1-0.5 part of pH adjuster, and 0.01-0.05 part of bactericide.

2. The all-water decorative film according to claim 1, characterized in that: The matting agent includes fumed aluminum oxide.

3. The all-aqueous decorative film according to claim 1, characterized in that: The printed substrate layer includes a printed PVC layer or a printed PP layer; the transparent substrate layer includes a transparent PVC layer or a transparent PP layer.

4. A method for preparing a fully aqueous decorative film according to any one of claims 1 to 3, characterized in that: The following steps are involved: S001. The acrylic modified waterborne polyurethane resin, polycarbodiimide, hydrophilic aliphatic polyisocyanate, defoamer, wetting agent, pH adjuster, bactericide and diluent are mixed to obtain a waterborne surface treatment agent; S002. Using a ceramic roller, the aqueous surface treatment agent is transferred to the upper surface of the transparent substrate layer, and dried at 50 to 60°C to cure the aqueous surface treatment agent to form a protective layer; S003. The printed substrate layer is subjected to corona treatment to make the surface tension of the printed substrate layer ≥38dyn / cm; S004. The water, the silicone-modified water-based polyurethane resin, the pigment and the wetting agent are uniformly mixed to obtain a water-based ink; S005. Using a gravure printing plate roller, the aqueous ink is transferred to the upper surface of the printing substrate layer, and dried at 50 to 60° C. to solidify the aqueous ink to form an aqueous ink printing layer; S006. Mix water, waterborne polycarbonate polyurethane resin, acrylic modified waterborne polyurethane resin, matting agent and thickener to obtain a waterborne back coating; S007. Using a ceramic roller, the water-based back coating is transferred to the lower surface of the printed substrate layer, and dried at 50 to 60° C. to cure the water-based back coating to form a water-based back coating; S008. Use a laminating machine to laminate the transparent substrate layer onto the water-based ink printing layer to obtain a fully water-based decorative film.

5. The method for preparing a fully aqueous decorative film according to claim 4, characterized in that: In step S002, the mesh size of the ceramic roller is 200-260 meshes.

6. The method for preparing a fully aqueous decorative film according to claim 4, characterized in that: In step S001, the viscosity of the aqueous surface treatment agent is 35-40s in Caien 3# cup.

7. The method for preparing a fully aqueous decorative film according to claim 4, characterized in that: In step S004, the viscosity of the water-based ink is 20 to 30 seconds in a Caien 3# cup.

8. The method for preparing a fully aqueous decorative film according to claim 4, characterized in that: In step S005, the mesh depth of the gravure printing plate roller is 15-25 um.

9. The method for preparing a fully aqueous decorative film according to claim 4, characterized in that: In step S006, the viscosity of the water-based back coating is 32 to 38 seconds in a Zain 3# cup.

10. The method for preparing a fully aqueous decorative film according to claim 4, characterized in that: In step S007, the mesh size of the ceramic roller is 200-260 meshes.

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